Brian Urlacher was coming back from a knee injury suffered in the final game of last season. His status and abilities were in question as he missed chunks of training camp reps. Urlacher’s situation seemed to be a springboard for worrying about the age of the Bears defense in key spots.

You couldn’t help but notice that Urlacher, Lance Briggs, Charles Tillman and Julius Peppers -- the key spots -- all were on the wrong side of 30. Decorated with Pro Bowls and all, sure, but the best part of the Bears was aging.

That, in turn, led to the expectation that the offense would have to carry the defense for the first time in the history of the Bears, or something like that.

The offense got almost all the new toys in the offseason, the shiniest being big wide receiver Brandon Marshall. Finally, the Bears would have a legit No. 1 wideout catching passes from Jay Cutler. Finally, the Bears offense would move into the modern NFL. Finally.

But then, no. The offense experienced fits and spurts, while the defense was going nuts. The defense took away the ball and took it into the end zone, sacking quarterbacks and drilling teams that deserved it. The defense was buying time for the offense.

But then, the defense slowed down, and finally pooped out against Seattle on Sunday. That was the worst. A rookie quarterback killed the Bears on 97- and 80-yard drives late in the fourth quarter and on the first possession of overtime.

The offense, meanwhile, even as Cutler-to-Marshall was everything you could hope for, was going nowhere important.

Now, Urlacher is hurt again. He might miss the rest of the season. Injuries have piled up. Quality depth is a question. The age and effectiveness of the defense screams trouble.

Yes, this is where we came in.

And yes, this is where the offense now has no choice but to carry this team.

And no, there is zero indication it is capable of doing that.

The Bears rank 30thin the NFL in offense, and thank goodness they get No. 32 Arizona later this month. It will mark the first time since the Jacksonville game, I believe, that the Bears won’t have the worst offense on the field. Something like that. Something bad and awful.

Break it down even more, and the Bears own the NFL’s second-worst passing offense, and thank goodness they play the worst in Minensota on Sunday. Think about that: The Bears have the second-worst passing offense even with Cutler-to-Marshall. That’s takes some doing, but the Bears are just the inept bunch to pull it off.

The line can be homicidal, and that was before the injuries. The tight ends are a joke, Devin Hester is a fraud, Earl Bennett is concussed, Alshon Jeffery apparently has a bonus clause for injuries, Eric Weems is a good kick returner, and Dane Sanzenbacher is slow and bad. Thanks for playing our game. Drive home safely, even if you can’t drive 80 yards on the field.

And here’s the thing: No matter how hard the Bears try to get with the program, they just can’t get that newfangled passing game and can’t lose their ability to run. The Bears rank 10thin the league in rushing, averaging more than 4.0 yards a carry and 120 yards per game.

But the Bears rarely stick with the run, a game-planning and play-calling flaw that is killing them. After three months, you are what you are. Good teams figure it out. So, why can’t the Bears? They might as well get off the bus running and stick with it if they want to give their sputtering defense a chance.

It always come back to the defense. In this case, the defense can’t get off the field on third down and the offense can’t stay on it consistently. When a pass-centric offense can’t stay on the field, it not only forces the defense back on the field, it does so while eating little clock -- a disaster when you should be protecting an aging and broken-down defense such as the Bears’.

The Bears are one of only four good teams in the top 10 in rushing. They’ve already lost to three of them (San Francisco, Houston and Seattle), and they would get obliterated by the fourth (New England).

Again, that brings us back to the defense, aging and slow and bad, and that was WITH Urlacher, who was aging and slow and bad himself on sideline-to-sideline plays he used to own. Urlacher couldn’t make those plays before the hamstring injury. Nobody made any plays when it mattered against Seattle. Now what?

Urlacher is out of contract after this season. He would be coming off another injury that ended his season early, which makes him Cutler-like, and that reminds me: Cutler is due for his annual season-ending injury. Hey, if you’re going to be a fatalist, I say, then be a fatalist.

Anyway, the point is, last Sunday might’ve been Urlacher’s last game as a Bear. If his injury at the end of Sunday’s monumental collapse signals a second straight death spiral to end another Bears season out of the playoffs, then Urlacher’s exit would come just four games ahead of Lovie Smith’s.